Five more arrests were made on Monday in connection with a foiled terrorist plot to bomb Hong Kong's courts and transportation networks, bringing the number of suspects arrested in the case to 14.

The five new suspects-four male and one female and aged from 15 to 37-include three students. They were arrested by the Hong Kong Police Force's National Security Department on suspicion of conspiring to commit terrorist activities-a violation of Article 24 of the National Security Law for Hong Kong.

The police said they were not ruling out further arrests.

On July 5, the police arrested nine people over the alleged bomb plot, including six secondary school students, a staff member at Hong Kong Baptist University, and his wife, who works at a Hong Kong secondary school.

Of the six secondary school students arrested last week, three have been charged with conspiracy to commit terrorism. They were denied bail after appearing at the West Kowloon Magistrates' Courts on Wednesday.

Police said the students were aided and recruited online and through street booths, and were promised assistance in fleeing Hong Kong after carrying out the plot before the middle of this month.

During the action last week, police seized triacetone triperoxide, a highly explosive chemical, in a hostel room in Tsim Sha Tsui that had allegedly been turned into a bomb-making laboratory.

About HK$600,000 ($77,250) in assets linked to the group was also frozen.

Days before the raid, a man attempted to murder a police officer on duty before committing suicide on the night of July 1. The case was deemed a "lone wolf-style act of domestic terrorism" after initial investigations by the police.

In a post on her official blog on Saturday and an article published in Hong Kong media on Monday, Secretary for Justice Teresa Cheng Yeuk-wah blasted "disgraceful "assertions by some Hong Kong scholars and teachers that the cases did not constitute "terrorism" since they were targeting the authorities, not civilians.

A serious criminal act is regarded as terrorism as long as it aims to provoke a state of terror to compel action by a government, Cheng said, citing United Nations' resolutions and worldwide anti-terrorism laws.

She underlined the necessity of raising public vigilance against terrorist activities and the "advocacy of terrorism", and said freedom of speech must not be used as an excuse for such calls.

Those who described such criminal acts as "heroic" or worth "gratitude" were immoral and confusing right and wrong, Cheng said.

An act of "propagating, defending or glorifying the theory and practice of terrorism" could constitute "advocating terrorism" under the National Security Law, she said.

Cheng said many countries, including the United Kingdom, Australia and France, have put in place laws to prohibit the advocating or glorifying of terrorism.